Use rtx_insn for more scheduler things, plus CONST_CAST_RTX_INSN

Use rtx_insn for more scheduler things, plus CONST_CAST_RTX_INSN

gcc/ChangeLog:
2014-09-05  David Malcolm  <dmalcolm@redhat.com>

	* sched-deps.c (sched_get_condition_with_rev_uncached): Strengthen
	param "insn" from const_rtx to const rtx_insn *.
	(sched_get_reverse_condition_uncached): Likewise.
	(sched_get_condition_with_rev): Likewise.
	(sched_has_condition_p): Likewise.
	(sched_insns_conditions_mutex_p): Likewise for both params.
	(sched_insn_is_legitimate_for_speculation_p): Likewise for param
	"insn"; convert use of CONST_CAST_RTX to CONST_CAST_RTX_INSN.
	(setup_insn_reg_uses): Move local "list" to be more tightly
	scoped, strengthening it from an rtx to an rtx_insn_list *.  Use
	its methods for clarity and type-safety.
	(sched_analyze_1): Strengthen local "pending" from rtx to
	rtx_insn_list *, and local "pending_mem" from rtx to
	rtx_expr_list *.  Use methods of each for clarity and type-safety.
	(sched_analyze_2): Likewise.
	(sched_analyze_insn): Likewise.

	* sched-int.h (sched_get_reverse_condition_uncached): Strengthen
	param from const_rtx to const rtx_insn *.
	(sched_insns_conditions_mutex_p): Likewise for both params.
	(sched_insn_is_legitimate_for_speculation_p): Likewise for first
	param.

	* system.h (CONST_CAST_RTX_INSN): New macro.

From-SVN: r214967